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Heterophoria 

le  Memorial  Lecture  of  the 
phthalmologlcal  Congress  1921 


By 

Ernest  E.  Maddox,  M.  D.,  F.  R.  C.  S.  Ed. 


Reprinted  from  Volume  3,  No.  1 

The  American  Journal  of  Physiological  Optics 

Published  by  the  Division  of  Ocular  Interests 

American  Optical  Company 


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Heterophoria 

Doyne  Memorial  Lecture  of  the 
Oxford  Ophthalmological  Congress  1921 


By 
Ernest  E.  Maddox,  M.  D.,  F.  R.  C.  S.  Ed. 


Reprinted  from  Volume  3,  No.  1 

The  American  Journal  of  Physiological  Optics 

Published  by  the  Division  of  Ocular  Interests 

American  Optical  Ckimpany 


^^^/  C.A\  Ty^tn-^ 


— .— mj — 

OPTOMETRY 
LIBRARY 


Heterophoria 

being  the  ."         •  '        .    •;  • 

Doyne  Memorial  Lecture  of  the  Oxford  Ophthalmo- 
logical  Congress  1921 

Ernest  E.  Maddox,  M.  D.,  F.  R.  C.  S.  Ed. 

THE  founder,  and  first  "master"  of  this  Congress, 
Mr.  Robert  W.  Doyne,  was  an  exceptionally  ardent 
benefactor  of  ophthalmology.  To  him  Oxford  practically 
owed  its  Eye  Infirmary,  and  the  University  its  diploma  in 
Ophthalmology. 

The  early  meetings  of  the  Congress  are  alive  with  memories 
to  many  of  us,  of  his  genial  presence,  setting  everyone  at 
ease,  even  including,  to  our  admiration,  those  unfortunate 
if  honoured  patients  upon  whom  members  of  the  Congress 
were  allowed  to  operate! 

On  later  occasions,  the  scene  changed,  and  'pathos' 
entered.  The  well-knit  frame,  inured  to  manly  sports, 
had  been  manifestly  overworked  (for  he  did  the  work  of 
two  men)  and  we  saw  the  evening  time  of  life  gathering 
about  him  all  too  prematurely;  illustrating  how 

"Swift  to  its  close  ebbs  out  life's  little  day, 
Earth's  joys  grow  dim,  its  glories  pass  away," 

Among  many  other  mementoes,  he  has  left  this  Congress 
behind  him  but  not  without  first  committing  its  welfare 
to  the  able  hands   in  which   it  has  continued   to  prosper. 

Introduction 

We  owe  the  name,  and  most  of  the  classification,  of 
heterophoria  (which  means  a  'tendency  to  differ'),  to 
George  Stevens,  of  New  York,  whose  English  ancestors, 
it  is  interesting  to  note,  were  ancient  benefactors  of  Wadham 
College,  Oxford.     For  twenty  years  before  his  dav,  hetero- 

25 


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AMERICAN  JOURNAL  OF  PHYSIOLOGICAL  OPTICS 

j5horia  Was^'ftidied  under  other  names,  such  as  'insufficiency' 
^nd'i&t^nt  doyi^t'ons,'  under  the  presiding  genius  of  von 
Gtde'fe,  ahd'I'nbtlce  in  the  literature  that  even  what  we 
now  call  hyperphoria  was  corrected  by  Mr.  W.  A.  Brailey, 
more  than  forty  years  ago. 

Heterophoria  is  a  tendency  to  imperfection  in  the  oculo- 
motor apparatus,  so  let  us  first  glance  at  that  apparatus 
itself.  To  begin  with,  there  are  several  things  it  shares  in 
common  with  the  rest  of  nature,  viz.  ow  the  surface  diversity 
and  beauty,  and  under  the  surface,  unitv,  balance,  habit 
and  rhythm. 

The  diversity  of  nature  is  very  evident,  but  the  under- 
lying unity  is  just  as  real.  Gravitation,  for  instance, 
binds  the  whole  universe  in  one,  while  radiant  energy  every- 
where fills  it  with  light  and  warmth.  The  same  laws  of 
motion  which  guide  a  schoolboy's  marble,  are  implicitly 
obeyed  by  the  remotest  planet.  This  principle  of  diversity 
in  unity  is  found  in  every  object  of  nature,  for  the  small 
re/3ects  the  great.  It  is  strikingly  so  in  living  organisms, 
ane  is  particularly  well  seen  in  the  eyes.  The  cerebral 
hemispheres  make  the  brain  appear  double,  yet  it  is  really 
one,  and  the  eyes  are  windows  (also  two  in  one)  through 
which  that  most  deeply  hidden  of  all  the  systems,  the  central 
nervous  system,  comes  to  the  surface  to  look  out  upon  the 
world.  It  is  no  wonder,  therefore,  that  Hering  long  ago 
described  the  eyes  as  a  single  organ  with  two  limbs.  This  single 
organ  he  called  the  'Doppelauge'  and  located  it  virtually 
behind  the  root  of  the  nose.  I  have  ventured  to  name  it 
the  'Binoculus'  as  more  easily  pronounced.  Pictures  on  the 
maculae  are  normally  referred  to  the  line  which  connects  the 
Binoculus  with  the  point  of  intersection  of  the  visual  lines. 
You  may  ask;  "If  the  eyes  are  virtually  one,  why  are  there 
two?"  The  duality  of  the  eyes  is  necessary  for  stereoscopic 
vision,  to  give  us  two  points  of  view  meeting  in  one;  for  a 
wider  field;  for  safety  in  the  event  of  accident  or  foreign 
body;  for  beauty  (for  could  you  imagine  yourselves  proposing 

26 


HETEROPHORIA— MADDOX 


to  a  Cyclopean  young  lady?  or  a  lady  with  three  eyes?),  and 
lastly  for  silent  eloquence;  for  eyes  can  speak,  and,  as  the 
poet  expressed  it,  "Soft  eyes  spake  love  to  eyes  which  spake 
again."  Together  with  the  lids  and  eyebrows,  the  eyes 
express  the  passing  emotions,  as  a  silent  lake  reflects  the 
changing  sky.  Just  as  the  mind  is  linked  with  the  cerebral 
cortex,  so,  it  would  seem  the  emotions  are  linked  with  the 
vegetative  nervous  system,  and  the  eyes  are  linked  with 
both,  for  they  express  both  thought  and  emotion.  Their 
link  with  the  vegetative  system  is  well  shewn  by  the  gastric 
disturbance  so  invariably  met  with  in  acute  glaucoma; 
and  conversely,  an  ice-cream,  as  Lucien  Howe  mentions, 
will  often  cause  a  brow-ache.  This  "reverse  action" 
has  a  great  bearing  on  heterophoria,  for  we  may  sometimes 
consider  it  the  cause  of  symptoms  when  itself  is  caused  by 
visceral  irritation.  As  regards  the  muscles,  nerves  and 
terminal  motor  nuclei  the  eyes  are  two,  but  with  respect 
to  all  higher  neurons  they  are  one. 

It  is  a  most  important  clinical  distinction  that  all  affec- 
tions of  the  final  common  paths  are  non-comitant,  while 
all  those  of  higher  structures  are  comitant.  Hence  in  the 
presence  of  comitancy  we  cannot  use  such  expressions  as 
'weakness  of  the  interni,  of  the  superior  recti,  the  obliques,' 
or  the  like.  It  is  not  that  such  conditions  are  impossible, 
but  if  they  are  present  non-comitancy  is  present.  If  the 
internal  recti  were  weak  there  would  be  increase  of  the 
defect  on  looking  to  either  side;  if  the  superior  recti,  there 
would  be  hyperphoria  on  looking  to  one  side,  and  the 
opposite  hyperphoria  on  looking  to  the  other  side,  and 
similar  'alternating  hyperphoria'  as  we  might  call  it,  would 
be  in  evidence  if  the  superior  or  inferior  obliques  were  weak. 
Every  intraorbital  explanation  of  comitant  deviatio77S  must  be 
fallacious. 

Divisions  of  Heterophoria 
The   first    great   division    of  heterophoria,    therefore,    is 

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AMERICAN  JOURNAL  OF  PHYSIOLOGICAL  OPTICS 


into  what  I  would  call  'lower'  and  'higher'  heterophoria, 
according  as  it  is  non-comitant  or  comitant.  It  is  clear 
that  we  need  two  different  kinds  of  charts,  one  for  the 
muscles  (Chart  I)  and  one  for  the  reflexes  (Chart  II),  and 
we  need  to  be  somewhat  on  the  alert  to  know  which  chart 
is  appropriate  to  a  special  case.  I  believe  all  reflexes  act 
through  the  higher  neurons.  No  single  muscle  is  afl^ected 
by  a  reflex. 

CHART  I 

muscue:      chart 


ELEVATORS 

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Lower  heterophoria — that  is,  heterophoria  due  to  one  or 
more  aflfected  muscles — is,  I  think,  very  often  over-looked, 
because  we  are  so  much  in  the  habit  of  confining  our  measure- 
ments to  the  primary  position  where  it  may  not  show  itself. 
The  four  diagonal  areas  of  the  motor  field  are  easily  in- 
vestigated by  the  disc  of  rods,  the  patient's  head  being 
placed  in  the  required  obliquity  before  a  large  tangent 
scale  on  the  wall.  If  the  disc  is  not  held  quite  in  a  vertical 
plane,  however,  the  red  streak  appears  curved,  which  may 
vitiate  the  test.  To  guard  against  this  I  employ  a  disc 
swung  as  from  a  gallows,  which  hangs  truly  without  being 
able  to  rotate  about  a  vertical  axis.  I  find  this  extremely 
suitable  for  measuring  the  torsion  of  the  false  image,  and 
I  have  asked  the  makers  of  my  tangent  scale  to  let 
the  scale  be  fixed  to  the  wall  by  a  single  screw  at  its 
centre  of  gravity,  to  allow  of  its  rotation  by  an  assistant, 

28 


HETEROPHORIA— MADDOX 


CHART  II 

Oculomotor  Reflexes 

{Suggested  Classification) 


KINGDOM  1:0R  HOME  OFFICE 

(To  Create  the  Binoculus) 

HORIZONTAL 

1  Convergence  (Eyes  approximate). 

2  Divergence  (Eyes  separate). 

VERTICAL 

3  Right  Hypervergence  (R.  rises  &  L.  falls). 

4  Left  Hypervergence  (L.  rises  &  R.  falls). 

TORSIONAL 

5  Incyclovergence  (Both  twist  in). 

6  Excyclovergence  (Both  twist  out). 

a  Function  =  Fusion                                    e   Involuntary 
b  Prevent  diplopia                                      f   Motions  contrary 
c   Unify  the  eyes                                         g  Stimulus  =  Desire  for  single  vision 
d  Take  account  of  third  dimension  of  h  More  linked  with  the   vegetative 
space  and  give  consciousness  of  dis-       system 
tance  of  objects                                       i    Meissner's  torsion 

KINGDOM  2:  OR  FOREIGN  OFFICE 
(To  direct  the  Binoculus) 

HORIZONTAL 

7  Dextroversion  (Both  turn  to  left). 

8  Levoversion  (Both  turn  to  left). 

VERTICAL 

9     Surversion  (Both  rise). 
10     Deversion  (Both  sink). 

TORSIONAL 

11  Dextrocycloversion  (Both  twist  to  right). 

12  Levocycloversion  (Both  twist  to  left). 

a  Function  =  Fixation                                 e   Mostly  voluntary 

b  Powerless  with  diplopia                         f   Motions  parallel 

c   Direct  the  gaze                                       g  Stimulus  =  Desire  for  macular  per- 

d  Take  account  of  first  and  second  di-       ception 

mensionsofspaceandgiveconscious-   h  Linked  with  labyrinths,  and  somatic 
ness    of  direction    and    attitude   of       equilibrating  system 
objects                                                         i    False  torsion 

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until  it  is  parallel  with  the  streak  of  light.  A  weak  vertical 
prism  before  the  other  eye,  or  clipped  on  to  the  disc  of  rods, 
makes  the  test  easier.  I  sometimes  use  a  rotating  wand 
attached  to  the  wall,  or  to  an  old  Bjerrum  screen,  by  a  nail 
through  its  centre.  The  diagnosis  of  paretic  muscles  is,  of 
course,  made  on  the  same  principles  as  for  frank  paralysis. 
I  still  think  that,  for  the  vertically  acting  muscles,  the  best 
method  is  that  outlined  in  my  book  on  the  Ocular  Muscles^ 
namely:  to  make  the  diagnosis  from  the  vertical  separation 
only,  and  then  confirm  it  by  the  torsion,  leaving  the  hori- 
zontal element  out  of  account. 

Let  us  now  consider  higher  heterophoria.  I  would  like  to 
draw  your  attention  to  the  twelve  beautiful  reflexes  of  which 
I  believe  six  preserve  the  eyes  in  one,  while  the  other  six 
make  them  dance  hither  and  thither  like  a  pair  of  merry 
children  hand  in  hand.  Some  of  them  are  familiar  to  you, 
others  probably  not.  They  are  in  six  reciprocal  pairs,  on  the 
"give  and  take"  principle,  and  they  no  doubt  have  the 
"reciprocal  innervation"  discovered  by  Sherrington. 

Hering  took  account  of  only  five  motions  in  framing  his 
theory,  and  modern  text-books  of  physiology  enumerate  no 
more,  but  in  ophthalmology,  others  have  gradually  made 
themselves  evident  during  the  last  thirty  years,  and  I  think 
now  all  these  twelve  are  definitely  proved,  except  the 
second,  in  favour  of  which  two  reasons  might  be  given,  and 
two  against.  I  have  tried  to  classify  them  into  natural 
orders,  as  shewn  in  this  chart. 

Another  list,  I  ought  to  say,  has  been  made  by  Professor 
Savage  of  Nashville,  a  list  of  ten,  but  difi^ering  from  mine  as 
being  on  the  lines  of  lower  heterophoria  instead  of  higher; 
that  is  to  say  they  are  in  terms  of  the  muscles.  The  most 
interesting  division  I  have  found  of  the  twelve  reflexes  is  into 
two  kingdoms  or  groups,  one  of  which  might  be  called  the 
'Home  Office,'  since  its  function  is  to  settle  the  domestic 
differences  of  the  eyes;  and  the  other  the  ^Foreign  Office' 
since  all  its  interests  are  abroad.     In  the  former  the  motions 

30 


HETEROPHORIA— MADDOX 


are  all  mutual,  /.  e.  towards  or  away  from  each  other;  in  the 
latter,  all  parallel.  These  two  groups  never  usurp  each 
other's  functions,  and  yet  work  in  perfect  harmony.  They 
are  like  a  white  man  and  a  black  man  working  harmoniously 
at  two  ends  of  one  saw,  and  yet  the  white  man  always  white, 
and  the  black  always  black.  Indeed,  what  Hering  found 
true  of  convergence  and  the  lateral  movements  of  the  eye 
may  be  extended  I  think  to  the  whole  of  each  kingdom. 

The  third  dimension  in  space  is  the  only  one  that  interests 
the  'Home  Office,'  while  the  'Foreign  Office'  is  exclusively 
concerned  with  the  first  and  second  dimensions.  The 
'Home  Office'  effects  fusion,  the  correction  of  diplopia,  and 
the  formation  and  preservation  of  the  binoculus.  It  cannot 
direct  the  binoculus  in  the  smallest  degree.  The  'Foreign 
Office'  alone  can  do  that  and  is  concerned  with  fixation, 
orientation,  equilibration  and  version.  The  'Home  Office' 
acts  under  the  stimuli  of  threatening  diplopia  of  six  dif- 
ferent kinds.  The  'Foreign  Office'  is  powerless  to  correct 
the  smallest  diplopia  of  any  kind  and  acts  under  the  stimuli 
of  volition  from  above,  combined  with  a  subordinate  fixa- 
tion reflex  from  below.  Miners  nystagmus  is,  I  believe, 
largely  due  to  a  conflict  between  volition  and  the  fixation 
reflex,  since  the  glitter  on  the  coal  solicits  the  latter  while  a 
blow  is  being  voluntarily  aimed  at  a  non-glittering  spot. 
This  is  only  by  the  way.  I  think  you  will  find  the  'Home 
Office'  is  more  in  touch  with  the  vegetative  nervous  system, 
and  the  'Foreign  Office'  with  the  somatic  nervous  system 
and  the  labyrinths.  This  is  a  very  interesting  distinction 
if  true,  explaining  why  worms,  indigestion,  and  teething, 
cause  not  parallel  deviations,  but  squints,  and  I  have  defi- 
nitely proved  my  own  slight  esophoria  to  be  increased  by 
gastric  irritation. 

These  two  kingdoms  may  therefore  be  looked  upon  as  two 
compound  reflexes,  playing  a  duet,  as  it  were,  upon  the  ter- 
minal nuclei  of  the  twelve  ocular  muscles.  They  never 
strike  single  notes,  but  always  chords.     That  is  to  say  they 

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AMERICAN  JOURNAL  OF  PHYSIOLOGICAL  OPTICS 

never  actuate  single  or  even  pairs  of  muscles.  Now,  I  have 
no  doubt,  since  the  same  chords  have  to  be  struck  again 
and  again,  that  linkages  are  formed  between  even  the  oculo- 
motor nuclei  of  the  3rd,  4th,  and  6th  nerves,  to  mechani- 
calise  the  work,  just  as  linkages  are  opened  up  to  the  spinal 
cord  for  the  fingers.  For  indeed  the  lower  motor  neurons  of 
the  ocular  muscles  are  in  series  with  those  in  the  anterior 
horns  of  the  spinal  cord,  just  as  the  ciliary  ganglion  is  in 
series  with  the  prevertebral  ganglia. 

The  Reflexes 

The  first  reflex  (to  take  them  now  in  detail),  is  an  old 
friend,  viz:  that  for  convergence^  the  slackness  of  which  causes 
exophoria,  and  its  excess  esophoria.  (I  prefer  the  English 
pronunciation  to  the  Greek  (esophoria)  as  distinguishing 
the  sound  better  from  exophoria.)  Fig.  1  shews  how  the 
visual  lines  are  approximated  towards  the  point  of  fixation  by- 
accommodative  convergence,  aided  by  postural  habit.  This 
is  the  coarse  adjustment.  The  small  bracket  represents  the 
fusion  reflex  which  effects  the  fine  adjustment.  It  not  only 
makes  the  lines  meet,  but  fastens  them  together. 

You  may  wonder  what  is  meant  by  the  larger  bracket. 
It  represents  a  fusion-reflex  augmented  by  voluntary  efi^ort. 
The  arrow  above  it  represents  directed  energy  from  above, 
perhaps  from  the  angular  gyrus,  which  Gordon  Holmes  has 
shewn  to  be  connected  with  visual  attention. 

However  great  the  postural  defect  may  be,  if  compensatory 
hypertrophy  has  made  the  fusion  reflex  large  enough  to 
easily  overcome  it,  the  heterophoria  may  be  regarded  rather 
as  a  harmless  anomaly  than  as  a  pathological  symptom. 
But  the  moment  the  work  to  be  done  is  almost  as  great  as 
the  workman,  the  latter  begins  to  labour,  and  trouble  begins. 
The  fusion  reflex  then  borrows  energy  from  the  centrons  of 
neighbouring  reflexes,  and  from  the  cerebral  cortex,  in  the 
form  of  the  'forced  attention'  referred  to. 

Now  a  reflex  is  a  machine,  that  is  to  say,  a  labour  saving 

32 


HETEROPHORIA— MADDOX 


device,  far  more  economical  than  voluntary  effort.  Sher- 
rington has  shewn  how  especially  untiring  are  the  postural 
reflexes  connected  with  the  gravity  muscles  and  no  doubt 


//p  /p\ 


Fig. 


The  coarse  and  tine  adjustments  of  convergence.      Distance  posture 
dp.     Convergence  posture  r  p.     Fusion  posture/ p. 


something  similar  could  be  said  about  those  of  the  eyes, 
especially  of  the  Home  Office.  We  have  lately  heard  from 
him  that  the  katabolic  waste  of  voluntary  motion  is  half  a 
million    times    greater    than    of  these     postural    reflexes. 

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AMERICAN  JOURNAL  OF  PHYSIOLOGICAL  OPTICS 

Whether  the  figure  is  correct  or  not  it  at  least  makes  us 
think.  The  cortex  is  the  last  part  of  the  brain  to  mature, 
and  the  first  to  fail,  and  its  exercise  is  the  most  tiring.  The 
angular  gyrus  lies  pretty  far  back,  and  the  cerebellum  has 
so  much  to  do  with  these  reflexes  that  the  frequency  of 
occipital  headache  in  uncompensated  heterophoria  is  not 
surprising,  especially  if  the  ablo-ascoid  muscles  are  also 
"wearied. 

Since  convergence  is  the  strongest  and  most  trainable  of 
all  the  reflexes,  its  slackness  (called  exophoria)  rarely  needs 
treatment  by  prisms.  Its  link  with  accommodation  enables 
us  to  influence  it  by  spherical  lenses,  a  treatment  which  next 
to  constitutional  measures,  is  the  best.  The  correction  of 
astigmatism  also,  and  of  hyperphoria,  helps  to  preserve  the 
converging  reflex  from  being  robbedof  its  energy.  For  eso- 
phoria  we  use  lenses  vj\\\c\\fully  correct  hypermetropia.  For 
exophoria,  generally  those  which  partially  correct  it;  but 
not  always,  for  in  neurasthenia  a  full  correction  may  be  best. 
"Exophoria  with  hypermetropia"  has  always  been  a  great 
puzzle,  but  I  think  it  due  to  a  limited  amount  of  nervous 
energy,  of  which  so  large  a  share  is  needed  for  accommoda- 
tion as  to  leave  too  little  for  convergence.  For  many  years 
I  have  treated  exophoria  in  healthy  young  people  by  concave 
lenses,  so  as  to  invoke  even  superphysiological  exercise  of 
accommodation,  and  thus  harness  their  abundant  accom- 
modative energy  to  the  task  of  sensitising  the  converging 
reflex. 

The  diverging  reflex  (No.  2)  is  the  only  one  I  have 
not  been  able  to  positively  prove.  Exophoria  from  "diver- 
gence excess"  is  still  only  a  theoretical  conception.  It  is 
moreover  almost  impossible  to  distinguish  between  inhibitory 
neurons,  acting  on  convergence,  and  a  positive  reflex  acting 
on  the  external  recti  as  its  efl^ectors.  However,  the  analogy 
of  the  other  reflexes  disposes  me  to  believe  in  the  latter. 
Indeed,  I  suggested,  thirty-five  years  ago,  in  the  Journal  of 
Anatomy   and  Physiology    that  the  external  recti  were  in- 

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HETEROPHORIA— MADDOX 


nervated  by  the  sympathetic  in  antagonism  to  convergence, 
just  as  the  dilator  pupillae  antagonises  the  sphincter.  In 
any  case,  there  must  be  some  mechanism,  the  proper  stimulus 
of  which  is  threatened  homonymous  diplopia,  and  which 
when  damaged  by  haemorrhage  causes  sudden  convergent 
strabismus.  So  I  have  ventured  to  include  it  in  my  chart, 
with  all  deference  to  Sir  George  Berry's  able  arguments 
otherwise.  Convergence  may  possibly  be  governed  by 
vagotonic  fibres  if  my  thought  of  sympatheticotonic  control 
of  divergence  is  correct. 

I  think  all  the  reflexes  of  Kingdom  I  are  (to  borrow  Sher- 
rington's term)  postural,  and  those  of  Kingdom  II  phasic. 
Certainly  the  vergences  are  less  powerful  than  the  versions. 
I  have  sometimes  thought  they  are  slower.  The  modern 
theory  that  the  sarcoplasm  is  controlled  by  the  sympa- 
thetic, and  the  sarcostyles  by  the  voluntary  motor  nervous 
system  may  if  true  have  a  bearing  on  the  two  main  groups 
of  oculomotor  reflexes. 

Nos.  3  and  4  are  remarkable  reflexes,  which  I  believe  to 
be  of  a  see-saiv  nature.  I  have  chosen  the  name  hyperver- 
gence,  not  because  it  is  the  best,  but  to  be  in  a  series  with 
hyperphoria.  If  a  prism  is  held  erect  before  one  eye  to 
test  the  prism  vergence,  that  one  eye  rises  to  overcome  it,  I 
believe,  by  one  of  these  see-saw  reflexes,  in  combination  with 
the  surverting  reflex  No.  9  which  simultaneously  raises  both 
eyes  equally,  to  preserve  the  naked  eye  from  displacement. 
This  arrangement  looks  so  needless  and  complicated  and  it 
would  be  so  much  simpler  for  each  eye  to  have  the  power  of 
monocular  adjustment  (Prism-duction),  that  for  many  years 
I  only  mentioned  these  see-saw  reflexes  as  probable  in  spite 
of  the  skew  deviation  of  the  eyes  sometimes  noticed  when 
the  middle  peduncle  of  the  cerebellum  is  damaged,  until  one 
day  I  had  a  remarkable  patient  who  later  went  by  the  name 
of  'Old  See-Saw,'  for  one  eye  rose  as  the  other  fell,  in  large 
regular,  slow  sequence.  This  settled  my  last  doubt.  A 
little  consideration  will  shew  that  such  an  arrangement  must 

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be,  if  each  of  the  two  Kingdoms  is  to  be  true  to  itself.  This 
figure  (Fig.  2)  shews  what  would  happen  were  right  hyper- 
vergence  to  take  place  by  itself,  while  Fig.  3  illustrates  the  sim- 


Fig.  2.     To  illustrate  the  "see-saw"  motion  of  right  hypervergence. 
(Note  immobility  of  Binoculus) 


Fig.  3.      Combined  right  hypervergence  and  (binocular)  surversion. 
(Note  rise  of  Binoculus) 

ultaneous  surversion  of  both  eyes,  by  reflex  9.  In  the  first 
figure  the  'Binoculus'  remains  stationary;  in  the  second  it 
is  raised  half  as  much  as  the  right  eye,  so  that  objects  appear 
displaced  upwards,  through  half  the  deviating  angle  of  the 
prism,  and  this  I  have  proved  to  be  the  case.  It  will  be 
noticed  that  the  see-saw  motion  alone  leaves  the  Binoculus 
unmoved.  It  is  most  important  that  the  mind  should  be 
sensible  of  every  movement  of  the  Binoculus,  and  since 
Kingdom  I  is  incapable  of  imparting  such  sensation,  it  defers 
all  movement  of  the  Binoculus  to  Kingdom.  II.  Herein  we 
detect  the  reason  for  an  arrangement  which  appears  needless- 
ly complicated.     It  enables  each  kind  of  reflex  to  mind  its  own 

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HETEROPHORIA— MADDOX 


business,  and  to  supply  correct  information  to  lieadquarters. 

The  normal  function  of  the  see-saw  reflexes  is  to  preserve 
the  fixation  lines  in  the  visual  plane.  When  we  wear  cylin- 
ders with  oblique  non-parallel  axes,  the  see-saws  are  in  con- 
stant alternating  exercise  as  we  look  from  side  to  side,  since 
the  prismatic  effect  of  the  lenses  is  such  as  to  cause  alter- 
nating hyperphoria.  This  is  one  of  the  chief  reasons  why 
oblique  cylinders  are  so  ill  tolerated. 

Since  the  hyperverging  reflexes  are  of  small  amplitude, 
hyperphorics  are  nearly  always  grateful  for  correction  by 
prisms.     They  are  the  least  trainable  of  all  the  reflexes. 

The  cycloverging  reflexes  (5  and  6)  cause  the  vertical  axes 
of  the  eyeballs  to  mutually  incline  towards  or  away 
from  each  other.  They  act  rather  more  on  the  obliques 
than  on  the  recti,  but  so  as  to  be  thoroughly  comitant 
in  their  effect,  which  could  not  of  course  be  possible  were 
they  to  act  on  the  obliques  only.  They  not  only  correct 
cyclophoria  but  have  I  believe  an  extremely  interesting  part 
to  play  in  ordinary  vision,  for,  if  I  am  right,  they  enable  the 
retinal  images  of  sloping  lines  in  the  median  plane  to  fall 
upon  corresponding  meridians.  If  I  hold  this  penholder  in 
the  median  plane,  but  with  its  upper  end  further  from  me 
than  the  lower,  reflex  6  (excyclovergence)  comes  into  play, 
otherwise  I  should  see  the  pen  double,  with  images  crossing, 
while  if  the  slope  of  the  pen  be  reversed,  so  as  to  bring  its 
upper  end  nearer  to  me,  reflex  5  (incyclovergence)  is  active. 

It  is  well  known  that  when  two  arrows  are  depicted  diverg- 
ing above  on  a  stereoscopic  card  they  appear,  when  fused,  to 
shoot  away  from  the  observer,  but  when  diverging  below  to 
shoot  towards  him. 

Cyclophoria  in  distant  vision  is  easily  measured  by  the 
glass  rods  as  already  described,  or  by  cyclophorometers, 
and  the  result  is  sometimes  valuable  in  helping  us  to  decide 
which  muscle  to  select  for  an  operation.  In  my  own  eyes 
there  is  slight  excyclophoria  when  fatigued,  as  by  a  long 
walk.     In  the  year  1890  George  Savage  discovered  the  prev- 

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alence  of  excyclophoria  in  near  vision  while  experimenting 
with  my  double  prism,  and  seven  years  later  George  Stevens 
published  his  first  paper  on  declinations.  More  than  sixty 
years  ago,  however,  a  torsion  of  the  eves  in  near  vision  was 
greatly  studied  by  Meissner  (1858),  Volkmann,  Helmholtz, 
and  others,  and  later  bv  Le  Conte. 

I  will  now  invite  vou  to  make  an  experiment  vourselves. 
Draw  an  upright  arrow  or  line  on  the  back  of  your  pro- 
grammes, and  hold  it  closer  to  your  eyes  than  the  near  point 
of  convergence  so  that  you  see  two  arrows.  In  all  proba- 
bility they  diverge  above,  shewing  excyclotropia,  since  the 
images  are  crossed.  If  now  you  raise  the  paper  so  as  to  look 
under  your  eyebrows  the  mutual  slant  increases,  but  if  you 
lower  it  so  as  to  look  down  as  far  as  possible,  the  arrows  be- 
come parallel.  This  proves  that  in  near  vision  there  is  a 
physiological  excyclophoria,  except  on  looking  down,  and 
that  it  gradually  increases  as  the  eyes  are  raised,  and  also, 
it  may  be  added,  as  the  object  of  fixation  is  brought  nearer. 
We  learn  from  this,  what  Helmholtz  pointed  out  from  Meis- 
sner's  test,  that  in  near  vision  the  primarv  position  of  the 
eyes  is  one  in  which  the  visual  plane  is  depressed,  and  indeed, 
we  naturally  cast  our  eyes  downwards  for  near  objects  to  let 
the  hands  and  eyes  work  together. 

If  noW'  you  look  at  the  same  arrow  with  the  eves  turned  up 
to  the  right,  you  may  notice  one  arrow-  rise  higher  than  the 
other,  while  with  the  eyes  turned  up  and  to  the  left,  the  other 
arrow  may  rise.  In  my  own  case  the  rising  arrow  indicates 
an  alternating  hyperphoria  which  points  to  comparative 
inaction  of  the  superior  recti  as  a  partial  cause  of  the  cyclo- 
phoria,  so  that  it  may  have  both  a  "higher"  and  "lower" 
element. 

Before  leaving  the  subject  of  cyclophoria  I  might  mention 
that  in  Professor  Savage's  list,  the  place  of  these  cycloverging 
reflexes  is  taken  by  what  he  calls  "harmonious  symmetrical 
action  of  the  obliques";  but  I  would  suggest  that  harmonious 
action   of  the  obliques   is   impossible.     Thev  would  cause 

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HETEROPHORIA— MADDOX 


CHART  HI 

Conjugate  Oculomotor  Nomenclature 


KINGDOM  I.  OR  HOME  OFFICE 

MOTIONS. 

PHORIAS. 

TROPIAS. 

1 

2 

3 
4 

5 
6 

Convergence 
Divergence 

R.  Hypervergence 
L.  Hypervergence 

Incyclovergence 
Excyclovergence 

Esophoria 
Exophoria 

R.  Hyperphoria 
L.  Hyperphoria 

Incyclophoria 
Excyclophoria 

Esotropia 
Exotropia 

R.  Hypertropia 
L.  Hypertropia 

Incyclotropia 
Excyclotropia 

KINGDOM  II.  OR  FOREIGN  OFFICE 

MOTIONS. 

PHORIAS. 

TROPIAS. 

7 
8 

9 
10 

11 
12 

Dextroversion 

Levoversion 

Surversion 
Deversion 

Dextrocyclo  version 
Levocyclo  version 

Dextrophoria 
Levophoria 

Anaphoria 
Kataphoria 

Dextrocyclophoria 
Levocyclophoria 

Dextrotropia 
Levotropia 

Anatropia 
Katatropia 

Dextrocyclotropia 
Levocyclotropia 

Vergences  are  contrary  motions  of  the  eyes  (mostly  involuntary). 

Versions  are  parallel  motions  of  the  eyes  (mostly  voluntary). 

Prism-vergences  are  changes  effected  in  the  mutual  posture  ot  the  eyes 
by  prisms  which  are  "overcome." 

Ductions  are  drawings  of  a  single  eye  in  any  direction  by  its  muscles. 

Torsion  means  twisting  of  an  eye  about  its  own  fixation  line  =  wheel- 
motion. 

Cyclovergence  means  mutual  contrary  wheel-motion  of  the  two  eyes; 
cyclotropia  the  result;  and  cyclophoria  the  tendency  thereto. 

Declination  means  angular  departure  of  the  vertical  axis  of  one  eye  from 
parallelism  with  the  median  plane  of  the  head. 

Phorias  are  "tendencies"  checked  in  Kingdom  I.  by  the  fusion  reflex;  and 
in  Kingdom  II.  by  the  desire  to  keep  the  head  straight. 

Tropias  are  "turnings,"  causing  in  Kingdom  I.  squint;  and  in  Kingdom  II. 
inclinations  of  the  head. 

The  prefixes  sur  and  de  are  contractions  for  "sursum"  and  "deorsum" 
(compare  surmount,  deject,  etc.). 

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"alternating  hyperphoria,"  for  on  looking  to  the  right  or 
left  the  elevating  power  of  the  ipsolateral  obliques  lessens, 
and  that  of  the  contralateral  obliques  increases.  At  the 
same  time  it  is  pleasant  to  own  that  his  theory  aimed  at  the 
true  thing;  it  only  needs  translating  from  lower  or  incomitant, 
into  higher  or  comitant  heterophoria  to  be  correct. 

The  first  four  reflexes  of  Kingdom  II  are  too  well-known 
to  be  dilated  upon.  They  were  named  "versions"  by 
Duane.  I  have  ventured  to  shorten  the  awkward 
prefixes  'sursum'  and  'deorsum'  into  'sur'  and  'de.'  These 
parallel  motions  are  both  voluntary  and  reflex.  In  their 
defects  no  diplopia  can  be  elicited  by  the  glass  rod.  There 
may  be  a  limitation  of  version,  /.  e.  of  parallel  movements 
of  the  eyes,  in  one  direction,  or  there  may  be  merely  a  pre- 
ponderance of  one  reflex  over  its  antagonist.  I  regard  it  as 
a'phoria  if  there  is  no  vicarious  inclination  of  the  head.  If 
the  head  be  turned  to  save  the  weak  verting  reflex  it  is,  I 
suggest,  no  longer  a  case  of  phoria  but  of  tropia.  Stevens 
made  a  great  study  of  anaphoria  and  kataphoria  (but  with- 
out making  this  distinction),  and  more  recently  Valk  has 
written,  well  and  ably,  on  dextrophoria  and  levophoria,  as 
studied  by  Stevens'  troptometer.  As  so  many  become  con- 
fused about  nomenclature,  I  have  drawn  up  chart  No.  III. 

The  cycloverting  reflexes  (11  &  12)  incline  the  vertical 
axes  of  the  eyeballs  parallelwise  to  right  and  left.  They 
are,  I  am  satisfied,  well  proved,  and  even  their  amplitude 
can  be,  to  some  extent,  measured.  They  enable  us  to 
judge  of  the  erectness  of  objects.  When  we  look  at  a 
picture,  for  instance,  to  see  if  it  is  straight  on  the  wall,  we 
instinctively  incline  our  heads  slightly  to  one  side  and  the 
other  to  put  these  reflexes  on  the  *qui  vive.' 

It  is  only  in  this  indirect  way  that  they  might  be  called 
voluntary.  They  are  also  involuntary  steadiers  ot  the  eyes 
in  its  other  parallel  movements,  but  they  do  not,  as  some 
might  suppose,  either  cause  or  nullify  "false  torsion"  for  that 

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HETEROPHORIA— MADDOX 


is  already  perfectly  accounted  for,  as  a  simple  mathematical 
necessity,  by  composition  of  the  vertical  and  horizontal 
parallel  movements  of  the  eyes.* 

Lucien  Howe,  author  of  the  most  complete  textbook  on 
the  Ocular  Muscles,  has  suggested  a  number  of  other  innerva- 
tions for  the  oblique  movements  of  the  eyes,  but  as  I  cannot 
discover  these,  I  have  not  charted  them. 

Tests  for  Heterophoria 

Let  us  now  consider  a  few  tests  for  heterophoria.  That 
which  first  of  all  led  me  to  pay  attention  to  muscle  balance, 
was  the  discovery,  while  experimenting  with  two  pin  holes  in  a 
piece  of  paper,  that  I  had  a  slight  esophoria  for  distance. 
To  investigate  this  more  fully,  and  at  the  same  time  find 
out  how  one  eye  would  behave  if  placed  in  the  dark,  I  con- 
structed this  dark  box  nearly  forty  years  ago,  and  it  was 
kindly  shewn  by  Mr.  Nettleship  to  the  Ophthalmological 
Society.  Its  aim  was  to  utilize  the  blind  spot  to  record  the 
movements  of  a  darkened  eye.  I  found  by  its  use  that  I 
had  an  exophoria  of  about  one  metre  angle  in  near  vision 
and  to  my  surprise  a  great  many  others  had  similar  devia- 
tions of  varying  degree,  so  much  so,  that  for  a  time  I  called 
it  "physiological  exophoria,"  a  name  which  I  have  now  aban- 
doned since  it  might  make  the  numerous  exceptions  which 
occur,  especially  in  young  people,  to  be  thought  unphysio- 
logical.  Von  Graefe's  test  for  near  vision,  till  then  univer- 
sally employed,  consisted  of  a  dot  with  a  line  through  it, 

*Professor  Savage  has  published  a  theory  that  in  the  oblique  movements 
of  the  eyes,  the  vertical  axes  of  the  eye-balls  are  preserved  in  parallelism  with 
the  median  plane  by  'harmonious  non-symmetrical  action'  of  the  obliques, 
that  is  to  say,  the  right  superior  oblique  working  with  the  left  inferior,  and  the 
left  superior  with  the  right  inferior.  I  regret  my  inability  to  endorse  the 
views  of  so  earnest  a  worker,  for  to  begin  with,  the  vertical  axes  of  the  eye- 
balls do  become  inclined  to  the  median  plane  in  the  oblique  movement  of  the 
eyes  as  a  necessary  consequence  of  Lishing's  law,  just  as  the  horizontal  axes 
become  inclined  to  the  horizontal  plane  in  the  opposite  sense:  and  secondly 
any  such  combined  action  of  the  pairs  of  obliques  named  would  result  in  a 
vertical  squint.  For  example,  if  the  right  superior  oblique  were  to  act  with 
the  left  inferior  oblique,  the  right  eye  would  sink  and  the  left  rise. 

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reduplicated  by  a  prism,  base  down  before  one  eye.  It  did 
not  seem  to  occur  to  von  Graefe  that  the  overlapping  of  the 
portions  of  the  line  would  suffice  to  maintain  fusion,  so  that 
his  test  only  revealed  deviations  in  extreme  cases,  and 
led  to  the  belief  that  the  normal  relation  between  conver- 
gence and  accommodation  was  a  fixed  one.  I  must  resist 
the  temptation  to  describe  a  number  of  other  experiments 
with  this  box  from  which  indeed  I  learned  most  of  what  little 
I  know  about  oculomotor  physiology.  A  better  way  of 
using  it  is  to  disregard  the  blind  spot  and  make  the  two 
points  of  light  appear  one  over  the  other  when  the  deviation 
can  be  read  off  direct.  Its  findings  were  confirmed  by  two 
other  tests;  which  occurred  to  me  all  the  same  time,  namely: 
the  double-prism  and  the  arrow  tangent-scale,  both  of  which 
were  much  used  for  some  years  until  the  first  begat  the  rod- 
test,  and  the  second  the  wing-test.  Perhaps  the  prettiest 
appliance  I  have  made  is  the  twin-test,  consisting  ot  two 
celluloid  sheets  of  complementary  colours  in  apposition,  and 
so  pricked  through  that  designs  appear  which  can  be  brought 
to  coincide.  My  near  vision  phorometer  also  in  complementary 
colours  is  quite  good  if  well  made,  but  I  have  not  brought  it 
today,  for  neither  method  secures  the  accommodation  quite 
so  well  as  the  wing-test.  I  find  in  practice  that,  on  the 
principle  of  the  survival  of  the  fittest,  I  have  gradually 
dropped  all  other  tests  except  the  rods  for  distance,  and  the 
wing  for  near,  supplemented  by  the  redress  and  the  parallax 
tests  (the  latter  so  ably  advocated  by  Duane),  and  my 
prism-verger  occasionally.  I  think  no  refraction  is  com- 
plete without  measuring  both  the  distant  and  the  near  pos- 
ture. The  rod-test  you  probably  know  already;  I  like  it 
made  with  very  thin  rods,  and  not  too  small  in  area.  It  is  best 
used  in  a  room  dark  enough  to  avoid  adventitious  reflections, 
and  yet  with  enough  light  to  secure  accommodation.  I 
have  in  my  own  eyes  esophoria  of  1°,  but  if  one  eye  be 
screened  I  have  a  3/^°  only.  I  have  found  many  both  in  far 
and  near  vision  have  about  3^°  less  esophoria,  or  }/^°  more 

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HETEROPHORIA— MADDOX 


exophoria,  on  screening.  This  is  due  to  slackening  of  the 
converging  reflex  when  one  eye  is  completely  covered.  In 
the  wing-test  both  eyes  receive  a  natural  stimulus  to  accom- 
modation. I  have  crowded  the  wings  close  to  the  eyes  for 
horizontal  measurements  to  avoid  exciting  the  ciliary  muscle, 
for  objects  which  are  hopelessly  near  do  not  tempt  accom- 
modation. It  is  important  to  make  sure  that  the  apparatus 
is  correctly  made,  so  that  the  object  intended  tor  each  eye  is 
entirely  hidden  from  the  other.  I  have  provided  the  rotat- 
ing wing-test  with  a  means  of  measuring  cyclophoria,  both 
by  vertical  and  horizontal  lines,  using  the  distant  pillar  for 
the  first,  and  the  wings  set  nearer  and  cross-wise  for  the 
second.  You  will  generally  find  a  difference  between  the 
two  measurements,  due  at  any  rate  in  part  to  the  curious 
fact  investigated  by  Helmholtz  and  others,  though  denied 
by  Savage,  Stevens,  and  Le  Conte,  that  the  physiological 
dividing  line  between  the  two  lateral  halves  of  the  retina  is 
not  perpendicular,  but  slants  down  and  in.  I  have  investi- 
gated the  point  and  I  find  the  "Helmholtz  retina"  exists  in 
most  eyes,  but  not  in  all.  The  'wing-test'  is  of  great  service 
in  the  correction  of  presbyopia.  If  the  arrow  trespass  ever 
so  little  on  the  esophoric  side,  we  may  safely  increase  our 
correction,  while  an  unusual  degree  of  exophoria  will  make 
us  careful  to  keep  it  as  weak  as  we  can  without  loss,  though  of 
course  other  considerations  come  in  as  well.  The  most 
important  minute  of  a  refractive  consultation  is  that  in 
which  we  deliberate  what  reading  lenses  to  order. 

The  *wing-test'  can  also  save  us  sometimes  from  over-cor- 
rection of  hyperphoria.  We  may,  for  example,  find  2°  for 
distance  and  about  1°  in  near  vision.  For  hospital  use,  my 
rotating  pattern  is  rather  fragile,  and  I  have  for  many  months 
tried  to  puzzle  out  an  instrument  free  from  all  movements, 
and  therefore  stronger.  I  have  at  last  succeeded.  One 
fixed  chart  now  measures  the  horizontal  vertical,  and  tor- 
sional elements  all  "in  one  go."  After  the  horizontal  balance 
has  been  measured,  the  arrow  should  be  set  at  an  angle  that 

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makes  it  appear  horizontal  to  the  patient.     Then  we  can 
read  off  the  hyperphoria  and  the  cyclophoria. 

Treatment  of  Heterophoria 

The  treatment  of  heterophoria  becomes  a  simple  matter 
as  soon  as  we  thoroughly  understand  the  nature  of  a  case. 
Each  needs  taking  on  its  own  merits.  I  need  only  touch  on 
some  elementary  principles. 

1  Discover  the  cause  and  remove  it  if  possible. 

2  Correct  any  error  of  refraction  with  perhaps  a  little 
decentering  of  the  lenses  in  the  direction  of  relief.  At  the 
same  time  treat  the  constitution  with  any  necessary  advice 
as  to  regimen  and  the  use  of  the  eyes.  If  symptoms  entirely 
disappear,  no  more  need  be  done,  even  if  the  heterophoria 
remain.  It  will  almost  certainly  be  less  in  time,  since  every 
organism  tends  to  "come  to  itself"  when  freed  from  adverse 
influences. 

3  If  lateral  deviations  are  complicated  by  hyperphoria 
correct  the  vertical  deviation  first  and  the  lateral  will  very 
likely  correct  itself. 

4  If  after  the  above  treatment  some  symptoms  still  con- 
tinue, train  the  weak  reflex  or  the  weak  muscle  as  the  case 
may  be.  Training  is  chiefly  indicated  in  young  people. 
It  is  only  suitable  for  older  ones  when  they  are  possessed  of 
sufficient  vigour.  In  neurotic  or  neurasthenic  cases  it  should 
not  be  commenced  until  the  nervous  system,  both  ocular  and 
bodily,  has  been  strengthened,  and  should  be  commenced 
during  a  holiday  or  bracing  change.  Undue  recession  of  the 
convergence  near  point  (or  sub-convergence  as  I  like  to  call 
it)  can  be  trained  by  drawing  an  arrow  on  a  piece  of  paper  and 
approaching  it  to  the  eyes  again  and  again  while  endeav- 
ouring to  keep  it  single.  Reber's  lateral  version  exercises 
may  help  somewhat,  in  the  same  way  that  rowing  helps 
writers'  cramp,  by  bringing  fresh  blood  to  the  structures 
concerned  without  actual  exercise  of  the  weakened  neurons. 
Prism   exercises  come  next.     I   often   give  young  people  a 

44 


HETEROPHORIA— MADDOX 


second  pair  of  spectacles  resembling  those  they  wear,  but 
with  adverse  prisms  incorporated,  and  bid  them  wear  these 
training  spectacles  at  certain  favourable  hours  of  the  day. 
As  an  alternative  to  this,  one  or  two  "grab"  prisms  can  be 
slipped  on  to  the  spectacles  in  ordinary  wear.  Whenever 
the  prisms  are  more  easily  overcome  in  near  than 
in  distant  vision  they  can  begin  by  looking  at  a  point  on  the 
wall  close  up  to  it  and  then  receding  backwards  to  the  other 
end  of  the  room  repeating  this  again  and  again  early  in  the 
morning  or  after  breakfast  or  rather  before  the  eyes  are  tired. 
When  glasses  are  not  worn  I  order  prisms  set  in  circular  rims, 
so  that  as  the  reflex  is  strengthened,  the  base-apex  lines  can 
be  made  to  lie  at  greater  and  greater  angles  to  each  other  by 
rotating  the  prisms  in  the  frame.  Lastly,  the  most  powerful 
training  of  all  is  obtained  by  the  simultaneous  rotation  of 
two  prisms  as  in  my  prism-verger,  the  object  being  a  disc  of 
ivory  or  white  paper  in  the  centre  of  a  Bjerrum  screen.  My 
verging  prisms  {i.e.,  rotating  towards  or  away  from  each 
other),  can  be  conveniently  mounted  also  either  in  a  pho- 
rometer  or  in  a  stereoscope.  Training  in  the  consulting 
room  however  is  only  practicable  for  those  surgeons  who 
are  blest  with  sufficient  leisure. 

5  Operation.  This  generally  is  the  last  resort  after  we 
have  helped  nature  to  do  her  best.  It  is  invaluable  in  some 
cases  and  especially  when  we  can  convert  a  non-comitant 
deviation  into  a  comitant  one  (Duane).  Hence  before 
operating,  the  whole  field  should  be  measured  to  find  a  weak 
muscle,  the  operation  should  be  planned  so  as  to  simultan- 
eously correct  any  cyclophoria,  and  in  lateral  deviations  any 
hyperphoria.  Lastly,  the  strength  of  the  opposing  reflex 
should  be  measured  by  prism-vergence,  especially  for  a  tenot- 
omy. I  say  the  opposing  Teflex  because  it  is  not  enough  for 
the  opposing  muscle  to  be  strong.  (For  example,  however 
strong  the  internal  rectus  may  be,  we  shall  obtain  no  effect 
from  tenotomy  of  the  external  in  the  primary  position  if  the 
converging  reflex  is  inactive.     The  internal  rectus  may  be 

45 


AMERICAN  JOURNAL  OF  PHYSIOLOGICAL  OPTICS 

Strong  for  phasic  motions,  and  yet  the  posture  be  weak.) 
Exercise  of  the  convergence,  however,  may  often  be  trusted 
to  bring  about  a  sufficient  augmentation  of  the  reflex  to 
make  tenotomy  advantageous.  I  have  had  excellent  results 
from  graduated  tenotomy  of  an  inferior  rectus  for  old  stand- 
ing paralysis  of  the  opposite  superior  oblique  (restoring  the 
head,  for  example,  in  the  case  of  one  medical  friend  to  the 
erect  position,  after  being  tilted  for  years  toward  one 
shoulder).  Even  cyclophoria  is  sometimes  worth  operating 
for.  I  have  recently  seen  a  patient  on  whom  I  operated 
for  this  more  than  twelve  years  ago.  Previously  to  the 
operation  he  had  headache  without  intermission  for  seven 
years  dating  from  typhoid,  and  he  has  had  no  headache 
since.  But  these  operations  are  extremely  tricky,  and  in 
higher  heterophoria  it  is  rather  a  responsibility  to  convert  a 
comitant  defect  into  a  non-comitant  one  by  operation. 
Here  again,  however,  nature  comes  to  the  rescue,  and  grad- 
ually restores  more  or  less  comitancy  if  a  muscle  is  only 
tenderly  dealt  with  by  operation,  on  the  principle  of  "rever- 
sion to  organism"  as  we  might  call  it. 

The  most  successful  surgeon  is  the  one  who  respects  nature 
most.  You  may  perhaps  wonder  that  I  have  said  nothing 
about  the  evolution  of  the  oculo-motor  apparatus,  but,  gentle- 
men, when  I  look  at  your  intelligent  faces,  and  the  soul  in 
your  eyes,  I  cannot  bring  myself  to  believe  that  you  are  de- 
scended from  maggots  and  spiders  and  pigs.  The  whole  voice 
of  nature,  as  I  hear  it,  is  against  that  fantastic  theory. 
Nature  is  conservative  and  not  progressive.  She  reverts 
to  type  as  soon  as  the  reason  for  departure  from  it  dis- 
appears. When  I  see  a  piano,  I  do  not  at  once  jump 
to  the  conclusion  that  because  the  keys  are  in  progressive 
series,  therefore  they  must  have  evolved  out  of  one  another! 

I  thank  you,  gentlemen,  for  your  kind  attention,  and  I 
have  now  the  pleasure  of  laying  this  imperfect  lecture  as  a 
little  memorial  wreath  upon  the  tomb  of  our  friend  and 
benefactor,  Robert  Walter  Doyne. 

Glenartney,  Poole  Roaci, 
Bournemouth,  England. 

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